There are Strangers in my House

Lat weekend, our house went on the market. Since then, we've had about six showings with positive feedback. I'm certainly thankful that we've had so much traffic so far. But I still find myself biting my fingernails, wondering if and when an offer will come... and what that offer might be. Increasingly irrational thoughts stream through my mind: Will the offer be reasonable? Will it be enough to get us the down payment we need for our next place?  Will there be strange, impossible demands with the offer? Will a home inspection turn up some unknown, crazy issue that none of us expected? Or... what if an offer never comes, and we have to live here for the rest of our lives? Okay, I know that last one is a little far-fetched. 
When we bought the house, it was a fixer upper. We've since invested a good bit of money and a lot of sweat into the property, essentially transforming every single room. But you know, it's still 117 years old. And you can't make an old house exactly like a new build. I find myself wondering "Will it have all been worth it?"

My husband--rightly so--tells me to stop worrying. To trust that would should be will be. Logically, I know that we don't have to accept--or even reply to--unreasonable offers. We can't foresee the future; we can only plan for and do the best we can. We just have to trust for the rest. 
Yet every time I take the pup and leave the house so a realtor can show the home to a potential buyer, I feel a nervous flutter in my stomach. When I come back and catch a whiff of a stranger's perfume, a small sadness twinges in my belly. We've made good memories here. Enjoyed so many home-cooked meals at that table. Laughed over drinks with friends in this living room. We've patched and repainted the nail holes where my artwork hung, fixed the dent in the stairwell where Mark fell down the stairs, repaired the two little scratches in the hardwood from Solo's puppy paws. 

I have to remind myself that it's not the house that matters: but the family and the memories made within beneath its roof. After all, we're just a little blip in this house's long history. Many families came and went before we arrived; and more will come and go after. 
I'm trying to look forward, towards our next adventure, but it's hard to feel a little nostalgic for what we're leaving behind and nervous for what lies ahead. 
Have you ever sold a home? Have any advice for surviving the process?